DE19933875B4 - Linear roller bearing for transmitting torques - Google Patents

Abstract

Linear roller bearing (1, 9, 16) for transmitting torques about its longitudinal center axis with an inner profile element (2, 10, 17) and an outer profile element (3, 11, 19) at least partially surrounding the inner profile element (2, 10, 17) wherein - the inner profile element (2, 10, 17) and the outer profile element (3, 11, 19) are arranged to be displaceable relative to one another in the longitudinal direction, - the inner profile element (2, 10, 17) has a cross-section deviating from a circular shape and with at least two outer wall sections (2a, 10a, 17a) pointing outwards and transmitting the torques are provided, - each outer wall section (2a, 10a, 17a) is assigned at least one inner wall section (3a, 11a, 19b) of the outer profile element which transmits the torques - the outer wall section (2a, 10a, 17a) and the inner wall section (3a, 11a, 19b) are mounted to one another by means of rolling elements (5, 14, 22) and - the rolling elements (5, 14, 22) in at least one Rolling elements mlauf (4, 13, 24) are guided and wherein the rolling element circuit (4, 13, 24) the rolling elements (5, 14, 22) in the longitudinal direction of the linear roller bearing (1, 9, 16) in a first guide track (4a, 13a, 24a) leads through a load zone and the rolling elements (5, 14, 22) then by means of a second guide track (4b, 13b, 24b) through a load-free zone, with the rolling element circulation (4, 13, 24) in an area between the inner wall section ( 3a, 11a, 19b) and the outer wall section (2a, 10a, 17a) arranged cage (6, 12, 18) is formed and at least one of the profile elements (2, 3, 10, 11, 17, 19) at least one on the loaded rolling elements (5, 14, 22) has acting pretensioning means for backlash-free tensioning of the profile elements (2, 3, 10, 11, 17, 19) against each other and the pretensioning means by at least one spring-elastic track section (8, 15a, located in the load zone, 23b) on at least one of the mutually associated wall sections (2a, 3a, 10a, 11a, 17a, 19b) is formed. characterized in that when the torques are introduced, at least the track section (15a, 23b) compresses so far that the wall sections (10a, 11a, 17a, 19b) assigned to one another move towards one another until at least one section (12a, 18a) of the cage (12, 18) transmits the torques from one of the wall sections (10a, 11a, 17a, 19b) assigned to one another to the other of the wall sections (10a, 11a, 17a, 19b) assigned to one another.

Description

Field of the invention

• – das innere Profilelement und das äußere Profilelement zueinander in Längsrichtung verschiebbar angeordnet sind,
• – das innere Profilelement einen von einer Kreisform abweichenden Querschnitt aufweist sowie mit mindestens zwei nach außen weisenden und die Drehmomente übertragenden äußeren Wandabschnitten versehen ist,
• – jedem äußerem Wandabschnitt wenigstens ein die Drehmomente übertragender innerer Wandabschnitt des äußeren Profilelementes zugeordnet ist,
• – der äußere Wandabschnitt und der innere Wandabschnitt zueinander mittels Wälzkörpern gelagert sind und
• – die Wälzkörper in mindestens einem Wälzkörperumlauf geführt sind

und wobei der Wälzkörperumlauf die Wälzkörper in Längsrichtung des Linearwälzlagers in einer ersten Führungsbahn durch eine Lastzone sowie die Wälzkörper anschließend mittels einer zweiten Führungsbahn durch eine lastfreie Zone führt.The invention relates to a linear roller bearing for transmitting torques about its longitudinal center axis with an inner profile element and an inner profile element at least partially enclosing outer profile element, wherein

• The inner profile element and the outer profile element are arranged displaceable relative to one another in the longitudinal direction,
• The inner profile element has a cross-section deviating from a circular shape and is provided with at least two outer wall sections facing outward and transmitting the torques,
• Each outer wall section is assigned at least one inner wall section of the outer profile element which transmits the torques,
• - The outer wall portion and the inner wall portion are mounted to each other by means of rolling elements and
• - The rolling elements are guided in at least one Wälzkörperumlauf

and wherein the Wälzkörperumlauf the rolling elements in the longitudinal direction of the linear roller bearing in a first guideway through a load zone and the rolling elements then leads by means of a second guideway through a load-free zone.

Background of the invention

Linear roller bearings are used in almost all areas of mechanical engineering and automotive engineering. With such bearings mutually longitudinally movable components are stored against each other. In applications with telescopically variable-length shafts, such a bearing must additionally transmit the torques guided by the shaft. Telescopically variable-length waves are z. B. used as steering shafts of steering columns modern motor vehicles. In such steering columns, the position of the steering wheel in the vehicle interior of the individual size and posture of the operator is customizable. This changes the absolute distance of the steering wheel to the steering gear. This change in distance can be corrected by two telescopically displaceable shaft ends arranged one inside the other. Since the steering shaft transmits the steering torque from the steering wheel to the steering gear, the steering shafts must also be rotationally coupled together. The position of the steering wheel is adjusted either manually by the physical strength of the operator or by electric motors. In both adjustment, the forces occurring in the sliding seat of the telescopically displaceable waves must not be too high. By means of a linear roller bearing arranged between the two shaft ends, the displacement forces are kept low and over the entire displacement range in a relatively constant size. Sometimes steering shafts are subject to changes in length during vehicle operation. These changes in length are short-stroke and oscillating and are caused by a relative movement of the steering gear with the lower end of the steering shaft to the relatively fixed upper end of the steering shaft.

The embodiments of the linear roller bearings used are different. In the above application linear bearings are often used for cost reasons that allow only a limited stroke of a component relative to the other component. These bearings usually have between the longitudinally displaceable components in a cage guided rolling elements. The cage tends to migrate during operation, especially in oscillating short-stroke movements. The rolling elements do not roll off but slide. The cage reaches in this way a position from the function-related stroke of the cage is no longer guaranteed. As a result, the rolling elements and the cage are exposed to forced movements which lead to sliding and inadmissible wear in larger strokes but also in short-stroke movements.

At first glance, therefore, the use of a linear roller bearing according to the prior art, which allows an unlimited sliding movement offers. These bearings are provided with one or more ball circulations in which the balls successively pass through a loading zone and then a load-free return zone and are guided back into the loading zone. Such a linear roller bearing is in DE 33 03 831 A1 described. In this case, a sleeve is provided inside and outside with Wälzkörperlaufbahnen and is covered inside and outside of Käfighälften. The rolling elements roll from the loaded inner zone on the inner diameter of the sleeve and the outer contour of the sliding shaft cage-guided in the unloaded zone and over the outer contour of the sleeve and from there back into the loaded zone. With the use of such bearings, the disadvantages of the initially mentioned linear bearings for limited stroke are avoided. However, they are relatively complicated and not run without clearance.

For reasons of comfort and function, it is often necessary that such bearings are designed without play. Play in a bearing between two ends of a steering shaft means reduction in steering quality and comfort loss due to possible rattling noises. The steering quality is negatively affected as there is radial play between the two steering shaft ends in a torsional play on the steering wheel expresses. The aforementioned rattling noises can be felt acoustically or by vibrations on the steering wheel and have an unpleasant effect on the operator. The initially mentioned linear bearings with limited stroke, however, can be designed without play with relatively simple means. So z. In EP 0 281 723 B1 describes a torque transmitting linear roller bearing, are supported in the Wälzlaufbahnen by spring elements on the inner component. The spring elements bias in rolling elements against the outer component. The play-free fit of the components to each other is guaranteed. Adjusting movements of the components in the longitudinal direction to each other by the rolling movement of the rolling elements smoothly and wear. The components are arranged with a small gap, ie with a measure that is the spring travel of the spring elements to each other. The spring elements are designed so that the rolling elements absorb any torque in the case of normal rotational forces. But if one is rotated against the other component under the effect of excessive torque, the spring elements spring so far until the components are adjacent to each other. The torque is now transmitted directly over the wall of the components and the rolling elements are relieved. The spring elements must be adapted to the normal rotational forces. So they work in normal operation already with relatively high bias. Under this high bias suffers the ease with which a linear bearing may have to work.

The US 3,353,875 A discloses a linear rolling bearing for transmitting torques about its longitudinal central axis. The linear roller bearing has an inner and outer profile elements, wherein the profile elements are braced against each other by means of a biasing means without play.

From the DE 68 09 633 U a linear roller bearing is known that comprises a biasing means, which is formed by a located in a load zone and resilient track portion on a wall portion.

The US 5 584 765 A describes a linear roller bearing, with an inner and outer profile element, wherein the outer profile element is formed by an outer ring of the linear roller bearing.

Summary of the invention

The object of the invention is therefore to provide a linear roller bearing, which avoids the disadvantages of the above-mentioned embodiments of linear roller bearings.

It is a linear roller bearing provided with recirculating ball, in which the Wälzkörperumlauf is arranged in a cage and the cage between an inner wall portion of an outer profile and an outer wall portion of an inner profile element is arranged, and that one of the profile elements at least one located on the in the Wälzkörperumlauf and loaded rolling elements acting biasing means for play-free pretensioning of the profile elements against each other. Such a linear roller bearing is simple and inexpensive to manufacture. Both the inner profile element and the outer profile element are easy to design and do not need to be provided with additional Wälzkörperlaufbahnen, Käfighalterungen or other for the rolling elements to necessary elements. The Wälzkörperumlauf is formed in Wälzkörperkäfig. The guideways of the rolling elements which are connected to a circulation with each other are introduced exclusively into the cage. The required space for the return of the unloaded rolling elements is simple means, such. B. by a groove with relatively large tolerances, with little effort in one or both of the profile elements introduce. The advantages of a linear roller bearing with Wälzkörperumlauf be used without taking the disadvantages mentioned initially in purchasing.

Such a bearing is easy to make free of play. It is carried out without play by the rolling elements located in the load zone are loaded with a biasing means against a wall portion of one or both profile elements are supported, while the biasing means itself is arranged on one or both of the profile elements. It is conceivable z. As the use of designed as a career spring plates. The spring plates are simply made by punching and bending or embossing of spring steel or spring steel similar hardened material and have z. B. on a curved profile in their cross-section. The spring plate is seen in cross-section curved to a degree that should be at least minimally larger than the largest possible theoretical game due to manufacturing tolerances in storage. The spring plate generates biased in the assembled state in the linear rolling a preload on the running on him loaded rolling elements. The loaded rolling elements are biased against the opposite wall portion. Such spring plates can also be inserted into both opposite or mutually associated wall sections. The sheet thickness of the spring plates and / or the execution of the curvature depends on the required bias. However, the bias voltage need not be so great as to transmit to the other wall portion via the spring plate and the rolling element torques. It is sufficient if these spring plates produce so much bias that the linear bearing is designed for longitudinal movements and play in the operating state.

The biasing means is formed by at least one located in the load zone and resilient trained raceway section on at least one of the mutually associated wall sections. Here again preferably the initially mentioned curved spring plate is to be used. In this case, however, the spring plate is curved only in cross section in the portion in which the load zone is located. The spring action is the same as that described in the previous section. Alternatively, a substantially flat sheet can be used, which is supported on one of the wall sections and generates by means of a lever, the bias on the loaded rolling elements. Such spring plates are produced with minimal effort. The spring preload can be influenced by the sheet thickness and the lever length.

This object is achieved according to the characterizing part of claim 1, characterized in that the load zone springs so far when initiating the torques that the mutually associated wall sections move towards each other until at least a portion of the cage, the torques of one of the associated wall sections to the other transmits the associated wall sections. The cage thus forms, in addition to a means for guiding the rolling elements, a means for transmitting the torques. The cage is arranged at a relatively small distance to each of the walls. About the distance of the cage to the walls of the size of the torque is determined, which is first transmitted by only the rolling elements. When this torque is exceeded, the load zone springs in and the walls move towards each other until they pinch the cage or the one section of the cage between them. The size of the torque, which is still transmitted through the rolling elements and raceways is determined by the design of the spring-loaded elements in the load zone and, as already mentioned by the distance of the cage to the wall.

It is therefore provided in a further embodiment, the resilient trained in the load zone career segment. In this case, such a raceway section may be formed either on a wall section, alternatively on the inner profile element or on the outer profile element, or on both mutually associated wall sections. It is further provided in this embodiment, that the spring-elastic trained career sections spring as far as the torque, the mutually associated wall sections move back against each other until they clamp the section of the cage between them or alternatively touch each other directly.

Further embodiments of the invention provide that the inner profile element is formed by an inner ring of the linear roller bearing and that the outer profile element is formed by a sleeve of the linear roller bearing. Such elements can be produced inexpensively in the chipless process but also by machining, in particular in mass production. The advantage of manufacturing individual elements is that the tubes and shafts in or on which such a linear roller bearing is used can be made relatively simple. The inner ring or the outer ring are preferably pressed into or onto the simply designed profiles. But it is also conceivable that the inner wall sections or the raceways for the flow of the rolling elements in the load zone is formed directly by the surface of the telescopically displaceable components. In such a case, it is particularly advantageous if the shaft elements and the associated outer tubes have a simple geometry. Therefore, it is provided with a further embodiment of the invention, the inner profile in its cross-section polygonal shape with at least three outer wall sections. Three outwardly facing wall sections ensure a uniform distribution of the forces resulting from the torque introduction on all load zones of the linear bearing. Regardless, however, rectangular, cuboidal or other polygonal cross-sectional shapes are used.

As already mentioned, parts made of spring steel sheets are simple and inexpensive to design and manufacture. A further embodiment of the invention therefore provides that at one or both of the mutually associated wall sections, a thin-walled resiliently trained raceway is provided and this track has a longitudinal groove in the region of the load-free zone. This longitudinal groove, preferably introduced by punching, ensures that the rolling elements in their circulation relieved and run back. Also in this embodiment, the track springs at least in the load zone so far that the mutually associated band sections move against each other until they touch each other or clamp a portion of the cage between them. For the compression in the corresponding profile element enough space is created. The spring plates are easily inserted into the profiles, snapped, welded or otherwise secured.

Finally, it is provided that the inner profile element is formed by a portion of a steering shaft and the outer profile element by the second portion of a steering shaft of a steering of a motor vehicle. Much of the components used for steering columns of modern motor vehicles is made by the non-cutting machining of sheet metal produced. Such steering columns must be easy to manufacture, have a low weight, take up little space, functionally reliable and comfortable to work. For this reason, the linear bearing according to the invention with its embodiments is particularly suitable for use between telescopically displaceable steering shafts.

Brief description of the drawings

The invention will be explained below with reference to several embodiments. Show it:

1 Sectional view of an embodiment of the linear bearing according to the invention with a rolling element circulation per wall section,

2 a further embodiment with two ball circulations per inner wall section and elastically formed raceways on both associated wall sections,

3 An embodiment of a linear roller bearing according to the invention with elastically resilient raceways, which are inserted in the outer profile element,

4 a sectional view through the linear roller bearing after 3 along the line IV,

5 a sectional view through the linear roller bearing after 3 along the line IV in an alternative embodiment to the 4 shown view and

6 a further alternative embodiment to the 4 shown view.

Detailed description of the drawing

In 1 is with 1 an embodiment of a linear roller bearing shown according to the invention. The linear rolling bearing 1 is by an inner profile element 2 , an outer profile element 3 and rolling element circulations 4 educated. The inner profile element 2 is z. B. formed on a lower portion of a steering shaft and the outer profile element 3 at an upper portion of a steering shaft. The inner profile element 2 is polygonal with three identically shaped outer wall sections 2a Mistake. Every outer wall section 2a is an inner wall section 3a of the outer profile element 3 assigned. Every outer wall section 2a is by means of rolling elements 5 at the associated inner wall portion 3a stored. Between each outer wall section 2a and inner wall section 3a is a cage 6 assembled. In every cage 6 is one of the rolling element circulations 4 formed in which the rolling elements 5 circulate. In the outer wall section 3a is a spring-trained track section 8th inserted. The raceway section 8th is seen in its cross section with a vault 7 fitted and preloaded in the linear roller bearing 1 assembled. The raceway section 8th transfers the bias over in a first guideway 4a of the ball circulation 4 located rolling elements 5 on the outer wall section 2a , The rolling elements 5 be in the first guideway 4a through a load zone of the ball circulation 4 guided. The ball circulation 4 also has a second guideway 4b on, in which the rolling elements 5 are guided through a load-free zone. The on three sides of the linear bearing 1 on the inner profile element 2 acting bias ensures the backlash of the linear roller bearing 1 from. Torques are from the inner profile element 2 by means of the outer wall section 2a over the inner wall section 3a on the outer profile element 3 and vice versa. Here are the inner profile element 2a and the outer profile element 3a to each other, as shown by the dashed line. The raceway section 8th is compressed in the load zone.

2 shows a further embodiment of the invention. A linear roller bearing 9 is by an inner profile element 10 , an outer profile element 11 and one the inner profile element 10 seen in cross section enclosing cage 12 educated. The inner profile element 10 is in turn with three outer wall sections 10a Mistake. Every outer wall section 10a are two rolling element cycles 13 assigned. The rolling elements 14 are again designed as spheres. The rolling elements 14 in a first guideway 13a of the rolling element circulation 13 are from two sides by a respective elastically trained raceway section 15a one as a spring plate 15 biased trained biasing element. In every outer wall section 10a and in each of the outer wall sections 10a associated inner wall section 11a is one of the spring plates 15 inserted. In a second guideway 13b of the rolling element circulation 13 run the unloaded rolling elements 14 back in a linear motion. Torques are from the inner profile element 10 over three sections 12a of the cage 12 to the outer profile element 11 transferred by the inner profile element 10 against the sections 12a the cage works and the cage 12 against the inner wall sections 11a the outer profile element presses and vice versa. The raceway sections 15a spring in the same or unequal parts.

3 shows with 16 a further embodiment of a linear roller bearing according to the invention. The inner profile element of the linear roller bearing 16 is through an inner ring 17 educated. The inner ring 17 embraces a cage 18 , The cage 18 is between the inner ring 17 and one as an outer ring 19 trained outer profile element arranged. The inner ring 17 sits on a wave section 20 , The outer ring 19 is in a not fully illustrated housing 21 pressed. The inner ring 17 has three identically formed outer wall sections 17a on. In the outer ring 19 are as biasing means spring plates 23 inserted. The spring plate 23 is on a lead 19a of the outer ring 19 added. The cage 18 points per outer wall section 17a two rolling element circulations 24 on. In a first guideway 24a a recirculating ball 24 go through loaded rolling elements 22 a load zone. This load zone is characterized by a resiliently biased raceway section 23b of the spring plate 23 generated. In the second guideway 24b the rolling elements run 22 relieved back. The rolling elements in the second guideway 24b are load-free, as they have a longitudinal groove 23a in the spring plate 23 the necessary space is created. Torques from the shaft section 20 be over the inner ring 17 and cage sections 18a as well as the inner wall sections 19b of the outer ring 19 on the case 21 transfer. The spring plate 23 springs in the area of the load zone.

4 shows a section through the linear roller bearing 16 to 3 , where the cage 18 is shown in plan view. In this view are the adjacent ball circulations 24 visible in the top view. The rolling elements shown in dashed lines 22 go through the load zone in the first guideway 24a , After passing through the first guideway 24a become the rolling elements 22 in the second guideway 24b diverted. The longitudinal groove 23a ensures that the rolling elements 22 load-free the second guideway 24b run through.

5 and 6 show alternative arrangements of the ball circuits 24 , In 5 are the ball rounds 24 in the longitudinal direction of the cage 18 seen offset but otherwise arranged aligned parallel to each other. 6 shows a cage 18 each of the mutually associated wall sections three ball circuits 24 having.

LIST OF REFERENCE NUMBERS

1

linear bearings

2

inner profile element

2a

outer wall section

3

outer profile element

3a

inner wall section

4

roller system

4a

first guideway

4b

second guideway

5

rolling elements

6

Cage

7

bulge

8th

Race section

9

linear bearings

10

inner profile element

10a

outer wall section

11

outer profile element

11a

inner wall section

12

Cage

12a

section

13

roller system

13a

first guideway

13b

second guideway

14

rolling elements

15

spring plate

15a

Race section

16

linear bearings

17

inner ring

17a

outer wall sections

18

Cage

18a

cage section

19

outer ring

19a

head Start

19b

inner wall section

20

shaft section

21

casing

22

rolling elements

23

spring plate

23a

longitudinal groove

23b

Race section

24

roller system

24a

first guideway

24b

second guideway

Claims (7)

Linear rolling bearings ( 1 . 9 . 16 ) for transmitting torques about its longitudinal central axis with an inner profile element ( 2 . 10 . 17 ) and one the inner profile element ( 2 . 10 . 17 ) at least partially enclosing outer profile element ( 3 . 11 . 19 ) whereby - the inner profiled element ( 2 . 10 . 17 ) and the outer profile element ( 3 . 11 . 19 ) are arranged displaceable relative to each other in the longitudinal direction, - the inner profile element ( 2 . 10 . 17 ) has a different cross-section from a circular shape and with at least two outwardly facing and the torques transmitting outer wall sections ( 2a . 10a . 17a ), - each outer wall section ( 2a . 10a . 17a ) at least one torque transmitting inner wall portion ( 3a . 11a . 19b ) is assigned to the outer profile element, - the outer wall portion ( 2a . 10a . 17a ) and the inner wall section ( 3a . 11a . 19b ) to each other by means of rolling elements ( 5 . 14 . 22 ) are mounted and - the rolling elements ( 5 . 14 . 22 ) in at least one rolling element circulation ( 4 . 13 . 24 ) and wherein the Wälzkörperumlauf ( 4 . 13 . 24 ) the rolling elements ( 5 . 14 . 22 ) in the longitudinal direction of the linear roller bearing ( 1 . 9 . 16 ) in a first guideway ( 4a . 13a . 24a ) by a load zone and the rolling elements ( 5 . 14 . 22 ) subsequently by means of a second guideway ( 4b . 13b . 24b ) passes through a load-free zone, wherein the Wälzkörperumlauf ( 4 . 13 . 24 ) in one between the inner wall section ( 3a . 11a . 19b ) and the outer wall section ( 2a . 10a . 17a ) arranged cage ( 6 . 12 . 18 ) is formed and at least one of the profile elements ( 2 . 3 . 10 . 11 . 17 . 19 ) at least one on the loaded rolling elements ( 5 . 14 . 22 ) acting biasing means for backlash-free clamping of the profile elements ( 2 . 3 . 10 . 11 . 17 . 19 ) against each other and the biasing means by at least one located in the load zone and resiliently trained raceway section ( 8th . 15a . 23b ) on at least one of the mutually associated wall sections ( 2a . 3a . 10a . 11a . 17a . 19b ) is formed. characterized in that at the initiation of the torques at least the raceway section ( 15a . 23b ) springs in so far that the mutually associated wall sections ( 10a . 11a . 17a . 19b ) move towards each other until at least one section ( 12a . 18a ) of the cage ( 12 . 18 ) the torques of one of the associated wall sections ( 10a . 11a . 17a . 19b ) to the other of the mutually associated wall sections ( 10a . 11a . 17a . 19b ) transmits. Linear rolling bearing according to claim 1, characterized in that the biasing means by at least one located in the load zone and resiliently trained raceway section ( 8th . 15a . 23b ) on at least one of the mutually associated wall sections ( 2a . 3a . 10a . 11a . 17a . 19b ) is formed, wherein the raceway section ( 8th . 15a . 23b ) springs in at the initiation of one of the torques so far that the mutually associated wall sections ( 2a . 3a . 10a . 11a . 17a . 19b ) move against each other until they reach a section ( 12a . 18a ) of the cage ( 12 . 18 ) between them. Linear rolling bearing according to claim 1, characterized in that the inner profile element by an inner ring ( 17 ) of the linear rolling bearing ( 16 ) is formed. Linear rolling bearing according to claim 1, characterized in that the outer profile element by an outer ring ( 19 ) of the linear rolling bearing ( 16 ) is formed. Linear rolling bearing according to claim 1, characterized in that the inner profile element ( 2 . 10 . 17 ) in its cross-section polygonal and with at least three of the outer wall sections ( 2a . 10a . 17a ) is provided. Linear rolling bearing according to claim 1, characterized in that the biasing means by a at least one of the mutually associated wall sections ( 19a ) arranged thin-walled and elastically resilient trained track section ( 23b ) is formed and the career section ( 23b ) in the unloaded zone with a longitudinal groove ( 23a ) and that the track section ( 23b ) springs in at the initiation of one of the torque at least in the load zone so far that the mutually associated wall sections ( 17a . 19b ) move against each other until they reach a section ( 18a ) of the cage between them. Linear rolling bearing according to claim 1, characterized in that the inner profile element ( 2 . 10 . 17 ) by a first portion of a steering shaft and the outer profile element ( 3 . 11 . 19 ) is formed by a second portion of a steering shaft of a steering of a motor vehicle.

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